Since electric appliances, such as a computer, a DVD recorder, and a cellular phone have added more various functions, operations of the electric appliances have become more complicated in recent years. Thus, the appliances have adopted interfaces to be operated in a menu-selection mode, and in particular, hierarchical interfaces operated in order to decrease complexity of the operations and to facilitate use of many functions of the appliances.
However, in such hierarchical interfaces, there are cases where the user has difficulties to understand descriptions of items to be displayed on a menu and where there is a conceptual gap in the descriptions of items between interface designers and users who actually use the appliances. For example, when a user operates a DVD recorder and desires to perform a task of translating subtitles into English, a gap occurs between an item imagined by the user who is to perform the task and an item to be actually displayed on a menu. Thus, a problem that the user cannot find a desired function arises. Since the user is confused about not finding a suitable function due to a conceptual gap between the interface designer and the user for the task, essentially in an interface to be operated in a menu-selection mode, the user is desirably provided with advantageous support for such a confused state.
Conventionally, apparatuses that solve such a confused state have been suggested (for example, see Patent Reference 1). The apparatus disclosed in Patent Reference 1 has functions each having related keywords assigned in advance thereto. The user presses a Help key and inputs keywords related to a function targeted by the user so that functions corresponding to the keywords are searched (help search). Thereby, the function targeted by the user can be estimated, thus realizing provision of operation support. However, there are cases where the apparatus in Patent Reference 1 has difficulties in assigning all keywords that are possibly inputted by the user, and where the user cannot input any appropriate keyword. In these cases, the apparatus cannot appropriately estimate a function targeted by the user.
Thus, in order to solve such a problem, apparatuses that estimate a target of a user using operation histories of the user have been suggested (for example, see Patent Reference 2).
Besides the aforementioned help search using inputted keywords, the apparatus disclosed in Patent Reference 2 generates operation histories until the time when the user presses a Help key, by assigning keywords to each of operation buttons and items to be displayed. Thus, this apparatus can estimate a function targeted by the user, using the operation histories to provide operation support.
FIG. 1 is a block diagram illustrating a configuration of the target estimation device disclosed in Patent Reference 2.
The target estimation device includes an input unit 2001, a required sentence storing unit 2002, a search unit 2003, a display unit 2004, a history information storing unit 2005, an operation-history vector generating unit 2006, and a function description database 2007. The input unit 2001 is included in a keyboard or a mouse, and accepts operation information and a keyword to be used in help search. The history information storing unit 2005 stores the operation information accepted by the input unit 2001. The operation-history vector generating unit 2006 generates a feature vector corresponding to an operation state, using an operation vector dictionary and operation information in N step that has been stored in the history information storing unit 2005 up to now. The search unit 2003 calculates an inner product of the feature vector corresponding to the operation state and each function description vector assigned to each function stored in the function description database 2007 so as to determine each score of the functions corresponding to the operation history (feature vector). Furthermore, the search unit 2003 also calculates scores using the help search, and in combination with the scores calculated using the help search and the scores by the feature vector, it searches a function to be an object for help, in other words, a function targeted by the user. The display unit 2004 displays, in order of the scores, functions obtained as a result of the search by the search unit 2003.    Patent Reference 1: Unexamined Patent Application Publication No. 7-121563    Patent Reference 2: Unexamined Patent Application Publication No. 2000-137726